The present invention relates generally to auditory prostheses and more particularly to auditory prostheses having adjustable acoustic parameters.
Auditory prostheses have been utilized to modify the auditory characteristics of sound received by a user or wearer of that auditory prosthesis. Usually the intent of the prosthesis is, at least partially, to compensate for a hearing impairment of the user or wearer. Hearing aids which provide an acoustic signal in the audible range to a wearer have been well known and are an example of an auditory prosthesis. More recently, cochlear implants which stimulate the auditory nerve with an electrical stimulus signal have been used to compensate for the hearing impairment of a wearer. Other examples of auditory prostheses are implanted hearing aids which stimulate the auditory response of the wearer by a mechanical stimulation of the middle ear and prostheses which otherwise electromechanically stimulate the user.
Hearing impairments are quite variable from one individual to another individual. An auditory prosthesis which properly compensates for the hearing impairment of one individual may not be beneficial or may be disruptive to another individual. Thus, auditory prostheses must be adjustable to serve the needs of an individual user or patient.
The process by which an individual auditory prosthesis is adjusted to be of optimum benefit to the user or patient is typically called "fitting". Stated another way, the auditory prosthesis must be "fit" to the individual user of that auditory prosthesis in order to provide a maximum benefit to that user, or patient. The "fitting" of the auditory prosthesis provides the auditory prosthesis with the appropriate auditory characteristics to be of benefit to the user.
This fitting process involves measuring the auditory characteristics of the individual's hearing, calculating the nature of the acoustic characteristics, e.g., acoustic amplification in specified frequency bands, needed to compensate for the particular auditory deficiency measured, adjusting the auditory characteristics of the auditory prosthesis to enable the prosthesis to deliver the appropriate acoustic characteristic, e.g., acoustic amplification is specified frequency bands, and verifying that this particular auditory characteristic does compensate for the hearing deficiency found by operating the auditory prosthesis in conjunction with the individual. In practice with conventional hearing aids, the adjustment of the auditory characteristics is accomplished by selection of components during the manufacturing process, so called "custom" hearing aids, or by adjusting potentiometers available to the fitter, typically an audiologist, hearing aid dispenser, otologist, otolaryngologist or other doctor or medical specialist.
Some hearing aids are programmable in addition to being adjustable. Programmable hearing aids have some memory device which store the acoustic parameters which the hearing aid can utilize to provide a particular auditory characteristic. The memory device may be changed or modified to provide a new or modified auditory parameter or set of auditory parameters which in turn will provide the hearing aid with a modified auditory characteristic. Typically the memory device will be an electronic memory, such as a register or randomly addressable memory, but may also be other types of memory devices such as programmed cards, switch settings or other alterable mechanism having retention capability. An example of a programmable hearing aid which utilizes electronic memory is described in U.S. Pat. No. 4,425,481, Mangold et al. With a programmable hearing aid which utilizes electronic memory, a new auditory characteristic, or a new set of acoustic parameters, may be provided to the hearing aid by a host computer or other programming device which includes a mechanism for communicating with the hearing aid being programmed.
In order to achieve an acceptable fitting for an individual, changes or modifications in the acoustic parameters may need to be made, either initially to achieve an initial setting or value for the acoustic parameters or to revise such settings or valuations after the hearing aid has been used by the user. Known mechanisms for providing settings or valuations for the acoustic parameters usually involve measuring the hearing impairment of an individual and determining the setting or value necessary for an individual acoustic parameter in order to compensate for the hearing impairment so measured.
A persistent problem in such fitting procedures is that the measuring and the adjustments in the acoustic parameters during fitting must be made using the auditory prosthesis itself which provides some practical difficulties. If the fitting procedure is automated, as is sometimes the case, the automatic features of the fitting process must be stopped and a physical, usually mechanical, adjustment of the acoustic parameters must be made while the auditory prosthesis is operated or utilized in conjunction with the user. Such manual, physical processes not only consume a lot of time but also involve the user, patient, of the auditory prosthesis and, thus, makes the fitting process long and arduous for the patient.